Steak generator



Jan. 27,1931. (J.IJ.NELIS V 1 7 STEAM GENERATOR I Filed April 16, 1928 INVEN OR JbSEPl/J 54/ BY g I W ORNEY Patented Jan. 27, 1931 -UNITED STATES PATENT OFFICE' JOSEPH JOHN NELIS, OF BROOKLYN, NEW YORK, ASSIGNOR TO FOSTER WE EELER COR- PORATION, OF NEW YORK, N. Y., l

A conrom'rron on NEW YORK STEAM GENERATOR The general object of the present invention is to provide a steam generator characterized by features of construction and arrangement whereby the generator is adapted for use in efliciently generating'steam at high pressures and giving the steam generated a high degree of superheat while keeping the required head room lower than has been the case with previous steam boilers capable of the same steaming capacity and other operating characteristics of the new steam generator and in which the center of gravity of the generator is at an appreciably lower level than in previous generators adapted for such use and also.

requiring no more head room.

The invention is characterized by the arrangement of the water heating surface of the generator in the form of a bank of so-called horizontal tubes; that is, tubes inclined at a relatively small angle to the horizontal and connected-at their ends to a lower water drum and to an upper steam and water drum, and the combination of this water heatingsurface with a radiant heat superheater which unites with the bank of water tubes to form a heat absorbing roof for all, or practically all of the length of a horizontally elongated combustion chamber and combined with a contra fiow economizer located above the bank of water tubes and having its top portion at approximately the same level as the top of the steam and water drum.

My improved steam generator was especially devised for. and is especially adapted for use in Mississippi River type towboats and like shallow draft river craft and to fit in the space heretofore commonly occupied in such vessels by the return tubular boilersheretofore in general use in such craft. My improved steam generator adapted for such use can be readily operated as to give as good a thermal efiiciency as is characteristic of good modern central station practice in which the efficiencies regularly attained are fully double those commonly attained with the return tubular boiler units which my improved steam generator is devised and adapted to replace. 4 V a My improved steam generator because of the charactenand particularly because of the Application filed April 16, 1928. Serial No. 270,205.

' simplicity of its construction, is well adapted for use with steam pressures as high as are now considered desirable for any service, that is, the generator may be constructed for steam pressures running from 200 pounds up to 1000 or 1200 pounds per square inch. The described superheating provisions permit of the ready attainment of such a substantial superheat as 100 or upward; The construction permits of the use of an economizer without infringement on the space requirements effective to reduce the temperature of the heating gases discharged to 300 F. or less and thus contributes materially to the efliciency obtained.

The improved steam generator. is characterized by a horizontally elongated combustion chamber, the volume of which is much greater than, about four-fold, that of the above mentioned return tubular boiler units,

and this increased volume of combustion chamber space and the other advantages referred to are obtained in my improved steam generator with its center of gravity at a substantially lower level than is'the case with such a return'tubular boiler as is referred to above of similar capacity and requiring the same over-all head room. This lowering of the center of gravity is of especial importance in the case of shallow river craft which are always top heavy and for that reason not infrequently capsize when struck by relatively moderate wind squalls. The generator is also characterized by having approximately half the weight of existing typesof marine boilers. While my improved steam genera--- tor may be fired in any usual or suitable manner, it is to be noted that the heat absorbing roof of the combustion chamber is of especial utility where the generator'is heated by the combustion of powdered coal or oil.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, and the advantages possessed by it reference should be had to the accompanying drawings and descriptive matter in which I .t

and side walls A and A", respectively, is

rovided with a horizontally elongated comustion chamber having a front section B and a rear section B partially separated by a bridge wall A A steam and water drum C, mounted transversely above the rear portion of the chamber section B is connected to a lower transverse water .drum D, sup ported externally of the combustion chamber section B The drums are connected by a '20 bank of horizontally inclined water tubes E.

The drum D is supported on a casting D located on the boiler room floor behind the lower part. of the generator rear wall A which is cut away to partially support the 5 drum. Each of the watertubes E enters the .drums C and D radially as shown in Fig. 1.

A curved intertube baflie F, supported on and cooled by the lower tubes .of the bank, extends from the bottom of the steam and water drum downwardly towards thewater drum D. An upper baffle G, mounted on and cooled by the uppermost row of water tubes E; extends from the rear wall of the boiler housing upwardly toward the steam and water drum C. The baflie G is substantially parallel with the major portion of the baflie F.

An economizer H preferably of the contra flow type comprising a horizontal casing I-I containing a plurality of horizontal gilled tubes H in staggered .relation is mounted above the baflie G. The gas inlet end of the economizer is in vertical alignment with the upper end of the bafileG. The generator rear wall continues upwardly from the top of the water drum D to the bottom of the economizer H and connects thereto adjacent the economiz er exit end. In some cases, the baffle G may be advantageously eliminated and the bottom of the economizer used as the upper limit of the gas passage. This portion of the rear wall is provided with a removable panel A permitting inspection and repairs to the rear end of the boiler. The top of the economizer casing H is approximately level with the 65 top of the steam and water drum C and connected to the side of the drum by an inclined wall J.

The steam and water drum C is provided at its front side with a pipe inlet connection C from the economizer water outlet (not shown). The pipe C is connected to the drum at a point below a horizontal bafiie C extending longitudinally of the drum. The baflle C is supported from the front side of the drum and extends transversely beyond the vertical center line of the drum. A steam outlet connection C is mounted in the front side of the drum 0 slightly above the baffle C Water gage connections 0 are shown at one end of the drum and a safety v alve C at the front side.

The upper end of the generator front wall A. is connected to the lower part of the drum M, respectively, while the superheater tubes of the section, adjacent the front end of the boiler are connected to the header M at one end and to an inlet header N adjacent the header L. The header N is connected to the steam outlet C of the drum C by a pipe N. The steam thus passes from the drum C to the header N, through the front superheater section to the header M from which it returns through the rear superheater section to the superheater steam outlet header L.

The steam generator shown can be fired with solid, liquid, powdered or gaseous fuel. although I have shown it as using solid fuel with a shaking grate P located in the lower part of the combustion chamber section B and extending between the front wall A and the bridge wall A of the boiler. Firing doors P and ash doors P are located in the lower part of the front wall above and below the grate respectively.

Soot blower tubes R are located at various points above the inclined bank of water tubes and among the economizer tubes. One of such tubes is positioned in a recess G formed by a portion of the bafile G. An inspection door S is arranged in the upper part of the boiler side wall adjacent the heating gas inlet to the economizer.

In the boiler construction shown, the burni-ng combustion gases pass upwardly from the grate P through the chamber section B. The gases are directed by the bridge wall up to the tubes and by the bafile F down along and in intimate contact with the lower parts of water tubes E through v the combustion chamber section B and pass around the lower end of the baffle F into the gas passage formed by the bafiies. F and G. The heating gases then pass upwardly among the upper rows of water tubes into the economizer H. from which the gases pass directly or indirectly to the stack. The superheater and the upper ends of the lower rows of water tubes absorb heat by radiation from the burning gases and the surrounding wall surfaces. The watherewith.

ter tubes also absorb heat by convection and conduction from the heated gases contacting scribed and the drum connections may be so arranged that the flow is upwards through all of said tubes if desired. The steam passing out of the upper ends of the tubes carries along slugs of water which are discharged against the baflie C and. prevented by the baflle from passing directly, to the superheater. This arrangement of the-baflle C separates the drum G into a lower water chamber and an upper steam chamber. The

'steam passes out through the connection N to the superheater.

While in accordance wlth the Provisions of the statutes, I have illustrated and described the best form of embodiment of'my invention now known to me, it will be apparent to those skilled in the art that changes may bemade in the form of the apparatus disclosed without departing from the spirit of my invention as set forth in the appended claims and that in some cases certain features of my invention may be used to'advantage without a corresponding use of other features. v

Having now described my invention what I claim as new and desire to secure by Letters Patent, is

1. A steam generator'ofa type havinga low center of gravity and requiring only 11mited head room, and comprising an upper transverse steam and water drum, a lower transverse water drum a substantial distance rearwardly thereof and connected thereto by 'a plurality of horizontally inclined water tubes, a combustion chamber projecting in front of the steam and water. drum and extending rearwardly therefrom to a point adjacent said lower water drum, an inclined battle extending rearwardly between'the tubes from the steam and water drum, a second inclined b'afile extending forwardly immediately above the uppermost water tubes, said baffies overlapping each other and providing a lower 'rearwardly and downwardly extending gas pass and an upper forwardly and upwardly extending gas pass, an economizer comprising a plurality oftransversely extending water tubes positioned above said low said drum bafiie, and a steam outlet con'-' nection from said steam and water drum above said drum baffle.

2. A steam generator of a type having a-low center of gravity and requiring only limited head room, and comprising an upper transverse steam and waterdrum, a. lower transverse water drum a substantial distance rears wardly thereof and connected thereto by a plurality of horizontally inclined water tubes, a combustion chamber rojecting in front .of the steam and water rum and extending rearwardly therefrom to a pointadjacent said lower water drum, an inclined 'baflle extending 'rearwardly between the tubes fromthe steam and water drum, a second inclined bafiie extending forwardly immediately' above the uppermost water tubes, said baflles overlapping each other and providin a lower rearwardly and downwardly exten V ing gas pass and an upper forwardly and upwardly extending gas pass, an economizer comprising a plurality of transversely extending water tubes positioned above said second battle and arranged to'receive gases passing out of the forward end of said upper gas pass, the over-all height of the generator I at said economizer being substantially the same as at said steam and water drum, a baflie extending horizontally in said steam and water drum above the points of connection of said water tubes 'to' said drum, a feed water conduit connecting a forward tube of said economizer-to said steam and water drum below said drum baflie, a horizontal roof portion for said combustion chamber portion in front of said steam and water drum, a radiant heat superheater having a plurality of steam conduit elements lining said horizontal roof portion, and a steam conduit connection from said steam and water'drum above said drum baffle'to said superheater. v

Signed at New York city,in the county of New York and State of New York this 12th day of April, A. D. 1928.

' OSEPH JOHN NELIS.

second baflie and arranged'to receive gases passing out of the forward end-of said upper gas pass, the overall height of the generator at said economizer being substantially the same as at said steam and water drum, a baflie extendingv horizontally in said steam and water drum above the (points of connection of rum, feed water conduits connecting the forward tubes of said economizer to said steam and water drum be- 

